DirecTV. I've been a customer for 10 years. Just upgraded since I just purchased a HDTV (Sony KDL-52XBR4 LCD). I had to get my dish upgraded to the new 5 LNB to receive the current/new HD channels. I also received/upgraded the receiver to the new HR21 HD DVR.
So far so good. The picture is amazing on HD specific content. Its generally better on most SD shows, but some of the old programming (Andy Griffith show, etc) the HD and higher resolutions really make the old programming look bad. Overall, I'm impressed with the new receiver compared to the Tivo based units I've used for the past 4-5 years.
It also have a home networking option with allows you to view pictures, video and play music from your PC's. Works great (pics so far) so one less box (media extender) I need to buy for the TV side of things.